Thanks JDH for offer of lilies.
The paper on orchids is by Hermann Müller [Verh. Naturhist. Ver. Preuss. Rheinlande & Westphalens 25 (1868): 1–62], on Platanthera and Epipactis.
Cites another work by P. Rohrbach [Über den Blüthenbau (1866)].
MS [of Descent] ready for printer.
Has read Bentham’s last Linnean Society [Presidential] Address [Proc. Linn. Soc. Lond. (1870): lxxiv–xciv] with great interest.